1. Field of the Invention
The present invention relates to a recording apparatus for recording by reciprocally moving a recording means.
2. Description of the Prior Art
A transfer recording apparatus such as a thermal transfer printer, a print head and an ink ribbon supply means are mounted on a carriage which is moved along paper. In a thermal transfer printer, a plurality of heat-generating elements mounted on a print head are generally driven in accordance with a print pattern signal.
The ink ribbon supply means comprises a supply reel and a take-up reel to supply an ink ribbon at a speed synchronous with the print speed. In general, a ribbon cassette which synchronously drives the takeup reel is used.
In a recording apparatus such as a printer, printing is performed only while the carriage is moved in one direction (print direction) and printing is not performed while the carriage is moved in the other direction (return direction). However, in order to improve the print efficiency, bi-directional printing in which printing is performed in both directions is being studied.
FIG. 1 shows a conventional cassette-type ink ribbon supply means. A supply reel 2 and a take-up reel 3 are arranged inside a cassette case 1. The cassette is mounted on a carriage (not shown). When the carriage is moved in a direction indicated by arrow F and a print head 4 is actuated, the take-up reel 3 is driven synchronously in a direction indicted by arrow A so as to feed an ink ribbon 5 in a direction indicated by arrow B.
When bi-directional print is performed by the ink ribbon supply means (ribbon cassette) as shown in FIG. 1, printing is performed also while the carriage is being moved in a direction indicated by arrow R. Therefore, the ink ribbon 5 must be supplied also in a direction indicated by arrow C. For this purpose, the supply reel 2 must be driven in a direction indicated by arrow D to serve as take-up reel.
In the conventional ink ribbon supply means as shown in FIG. 1, both the supply reel 2 and the take-up reel 3 must be driven, and the drive system therefore becomes complex in structure.
A portion of the ink ribbon which has been used for printing cannot be reused for the same purpose. For this reason, only after the ink ribbon 5 is fed for one line at an end position after printing one line in the forward direction (direction indicated by arrow F), printing in the reverse direction (direction indicated by arrow R) cannot be started. Similarly, at an end position after printing one line in the reverse direction, printing in the forward direction cannot be started until the ink ribbon is taken up for one line. For this reason, take-up of the ink ribbon is time-consuming and printing speed is lowered.